Skin-tight circuits could drive IoT to healthcare

May 30, 2016 // By Jean-Pierre Joosting
A team of University of Wisconsin-Madison engineers claim to have created the fastest stretchable, wearable integrated circuits, an advance that could drive the Internet of Things and a much more connected, high-speed wireless world.

The engineers have created a platform for manufacturers seeking to expand the capabilities and applications of wearable electronics particularly as they strive to develop devices that take advantage of a new generation of wireless broadband technologies referred to as 5G.

The stretchable integrated circuits feature a unique structure, inspired by twisted-pair telephone cables. They contain, essentially, two ultra-tiny intertwining power transmission lines in repeating S-curves.

This serpentine shape – formed in two layers with segmented metal blocks, like a 3-D puzzle – gives the transmission lines the ability to stretch without affecting their performance. It also helps shield the lines from outside interference and, at the same time, confine the electromagnetic waves flowing through them, almost completely eliminating current loss. Currently, these stretchable integrated circuits can operate at radio frequency levels up to 40 GHz.

Further, unlike other stretchable transmission lines, whose widths can approach 640 micrometers (or 0.64 millimeters), the these new stretchable integrated circuits are just 25 micrometers (or 0.025 millimeters) thick. That's tiny enough to be highly effective in epidermal electronic systems, among many other applications.

Fabricated in interlocking segments like a 3-D puzzle, the new integrated circuits could be used in wearable electronics that adhere to the skin like temporary tattoos. Because the circuits increase wireless speed, these systems could allow health care staff to monitor patients remotely, without the use of cables and cords. Image courtesy of Yei Hwan Jung and Juhwan Lee/University of Wisconsin-Madison.